Galvanometer fiber or string



Sept. 27, 1938. H. MANN 2,131,478

GALVANOMETER FIBER OR STRING Filed March 8, 1937 www IN VEN TOR.

Patented Sept. 27, 1938 UNITED STATES PATENT OFFICE 1 claim.

My invention relates to a new type of galvanometer ilber or string.

The string galvanometer consists essentially of a strong magnet between the poles oi' which is 5 suspended a tine conducting ber or string. Up to the present this conducting ilber or string has consisted of either a nely drawn metallic wire or fine lament of glass or quartz with a metallic coating. Because of the nature of the l0 instrument it is obvious to those skilled in the art that if two or more conducting systems could be combined into a single iilament the sensitivity of the instrument could be increased lmany-fold. The present invention relates to such a multiple string or iilament.

The present invention consists of a string or ber for the string galvanometer which is somade that it consists of two or more layers of conducting material separated from each other by non-conducting material. In this way a string can be constructed having a'core oi one material and several concentric layers,` each layer of conducting material being separated from the adjacent layers of non-conducting medium in such a way that while the combined product is a single string it nevertheless is capable of carrying two or more separate currents simultaneously or of multiplying the effects o! a single current by transmitting it through the several conducting '30 layers.

Itwill be obvious to those skilled in the art that such a multiple string ailords the opportunity of increasing many-fold the sensitivity of the ordinary string galvanometer and also that it permits the construction o! a string galvanometer in which the usual electromagnet can be reduced toaverysmallsiseorentirelyeliminatedandreplaced by a permanent magnet. Such an increase in sensitivity or decrease in size and weight will result in a much more useful and portable instrument.

In the drawing, Fig. 1 is an enlarged diagrammatic perspective view of the galvanometer string or fiber of my invention; and' Fig. 2 is a similarly enlarged end view.

As shown in the drawing, the central core I, represents the string or fiber which may be lo formed as a ne filament as is well known, of usual material, for instance, quartz or glass. 'I'he alternate layers 2, 4 and 6 are conducting layers and may be formed in the usual manner, for instance by metallizing the central core and non- 1g conducting layers 3 and 5 which separate and insulate the conducting layers'irom each other. Metals, such as gold, silver, or any well known conducting metal, may be used and may be deposited either with or without the aid of a vacum um, all as well known to those skilled in the art. The string or ilber is of the usual length used in string galvanometers and may be approximately ten centimeters long and 1,5000 to -1/0000 of an inch in diameter. The non-conducting coatings g5 3 and 5 may be formed on the conducting layers, by depositing in a manner well known in the art,

a nlm or non-conducting material, such as quartz, aluminum oxide and the like.

I claim: A n

A multi-layer conductive string, for use in a string galvanometer, consisting of alternate layers of conductive and non-conductive material, there being at least two conductive layers in the string.

HUBERT MANN. 

